一种高线性度宽带可编程增益放大器

A wideband programmable gain amplifier with high linearity

设计了一种应用于超宽带无线接收机的高线性度宽带可编程增益放大器(PGA),该PGA采用线性度增强型源简并结构的放大器加电阻衰减网络的结构,增益的调节分两步完成,PGA Core实现6dB增益调节步长,电阻衰减网络实现1dB增益调节步长,PGA Core电路采用线性度增强型源简并结构放大器,提高PGA的线性度。PGA采用SMIC 0.18μm混合信号CMOS工艺,1.8 V电源电压供电,仿真结果表明,该PGA增益范围-4~28dB,1dB步进,3dB带宽大于280 MHz,最大增益时输出三阶交调点(OIP3)25.7dBm,噪声系数(NF)22.24dB,总体电路消耗10.4 m A电流,芯片有效面积0.2 mm^2。

A wideband programmable gain amplifier（ PGA） with high linearity is designed for ultra- wideband wireless receiver. The PGA is composed of linearity enhanced amplifier with source degenerate and attenuator. Variable gain is achieved by two steps, the 6dB gain step is implemented by the PGA Core and the 1dB gain step is implemented by the attenuator. To improve PGA linear-ity, PGA Core adopts linearity enhanced amplifier with source degenerate. The PGA is implemented in SMIC 0. 18 μm 1. 8 VCMOS process. The simulation results show that the PGA achieves a dynamic range from- 4dB to 28dB with 1dB step and a 3dB bandwidth up to 280 MHz. The output third- order intercept point（OIP3） is 25. 7dBm and the noise figure（ NF） is 22. 24dB at the maximum gain. The quiescent current of PGA is 10. 4 mA. The chip area is 0. 2 mm^2.